The present invention relates generally to tool bar implements used in agriculture to carry ground engaging tools for preparing the ground for planting or for carrying the planter units themselves for planting seed into the ground, and, more particularly, to a tool bar implement that converts from a wide, transversely extending working configuration to a narrow, longitudinally extending transport configuration.
Modem farmers strive to improve the management of increasing amounts of farm acres. Improving management requires farmers to be able to quickly prepare the soil for each season""s farming operations. This haste has driven the need for more efficient and larger farming equipment.
Implements such as harrows, packers, or combined harrow-packers were some of the earliest implements to be made with widths exceeding sixty feet in the field operating position. As tractor horsepower has increased over time, larger tillage implements have been made available. These larger implements require a mechanism for compactly folding the implement for practical and safe transport over the highway.
The conventional method of folding tillage implements is by folding wing sections along forward aligned axes such that the wings are folded to a generally upright position. Double folding wing sections may have outer sections that fold inwardly and downwardly from the ends of inner wing sections in five section winged implements. In the case of these conventional wing implements, the minimum implement width that can be achieved by such folding is limited by the width of the center section. As a result, road transport may still be somewhat restricted as these implements often exceed twenty feet or more in transport width.
Road transport standards in North America are beginning to follow the standards set in Europe in which maximum road transport widths and heights for agricultural implements are being defined. Large implements that have conventional folding wing sections are not able to be folded such that they fall within width and height limits that may be generally 3 meters wide and 4 meters high. Some U.S. states have adopted transport width limits of 13.5 ft.
Forward or rear folding implements provide some relief with respect to such transport limits. However, implements must also be made to function with the accurate seeding ability that conventionally folded implements have become capable of. Although some rear or forward folding multibar tillage implements have been developed, they do not demonstrate the accurate depth control required for farming operations.
It is therefor desirable to provide a folding tool bar implement that is operable to convert between transport and field operating configurations.
Accordingly, an important object of the present invention is to provide a folding tool bar implement that converts between transverse field operating configuration and a longitudinal transport configuration.
It is another object of the present invention to provide a folding tool bar implement having a rotatable rockshaft supported on one or more caster wheels.
It is a further object of the present invention to provide a caster wheel with a first caster axis and a second caster axis such that the caster wheel caster wheel pivots in all directions on a first caster axis when the implement is in a field operating configuration and may be steerably controlled on a second caster axis by an actuator.
It is yet another object of the present invention to provide a caster lock that engages and disengages by gravity.
It is a further object of the present invention to provide tool frames that pivot on the rockshaft to follow uneven ground and maintain depth of ground working tools.
It is an object of the present invention to provide a folding tool bar implement in which the tool frames are attached to the rockshaft via slotted members such that both pivotal motion and motion along the slot is allowed.
It is an advantage of the present invention that the tool frames are raised in sequence so that all the tool frames of all wing sections are not raised at once, thereby minimizing the stress of the rockshaft.
It is a further advantage of the present invention that the tool frames in one wing section are all raised at once to minimize the length of hose attachments for hydraulics or air-seed delivery.
It is another object of the present invention to provide a limiting linkage that pivots to an over-center position to lock the tool frames when they are fully raised to a transport position.
It is yet another object of the present invention to provide springs on the tool frames which abut members on the rockshaft when the tool frames are in the working configuration and which may be used to transfer weight from the rockshaft to the tool frames to bias the tool frames toward the ground.
It is a further object of the present invention to provide a transport lock that locks the wing sections adjacent the main section when they are rotated rearwardly for transport.
It is another object of the present invention to provide actuators for raising or lowering the wing sections in a range of working positions.
It is yet another object of the present invention to provide a link on the rockshaft that operates a hydraulic valve to allow operation of the caster wheels in transport configuration but not in the field operating position.
These and other objects, features, and advantages are accomplished according to the present invention by providing a folding tool bar implement that converts from a transversely extending operating configuration to a longitudinally extending transport configuration. The implement includes a rotating rockshaft having a pair of wing sections pivotally connected to the opposing lateral ends of a center section. A plurality of individual tool frames are pivotally connected to the rockshaft sections and extend rearwardly thereof. Each tool frame is also supported by a rearwardly positioned support wheel connected to the rockshaft by a connecting link. The conversion of the tool bar implement begins with the rotation of the rockshaft from a first position to a second position to re-orient the pivot axis connecting the wing sections to the center section into a vertical orientation. The tool frames corresponding to the wing sections are then raised into a vertical orientation so that the wing sections can be pivotally folded rearwardly with the vertical wing section tool frames being positioned over top of the center section tool frames.
The foregoing and other objects, features, and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description that follows, in conjunction with the accompanying sheets of drawings. It is to be expressly understood, however, that the drawings are for illustrative purposes and are not to be construed as defining the limits of the invention.